我正在使用IDbCommandTreeInterceptor
在我的模型上启用软删除。
System.Data.Entity.Infrastructure.Interception.DbInterception.Add(
new SoftDeleteInterception());
我希望能够暂时禁用拦截器,以便我可以选择“已删除”的实体进行审核。
但是,似乎DbInterception
集合在程序集范围内。
有没有办法在没有拦截的情况下创建新的DbContext
?
甚至可以在每次创建拦截器时将其添加到DbContext
?
答案 0 :(得分:8)
我已经使用附加属性扩展了我的db上下文类
[DbConfigurationType(typeof(DbConfig))]
public partial class YourEntitiesDB
{
public bool IgnoreSoftDelete { get; set; }
}
然后在TreeCreated(...)方法中我检查这个标志,如果为true,那么它就不会进一步到QueryVisitor
public class SoftDeleteInterceptor : IDbCommandTreeInterceptor
{
public SoftDeleteInterceptor()
{
}
public void TreeCreated(DbCommandTreeInterceptionContext interceptionContext)
{
var db = interceptionContext.DbContexts.FirstOrDefault() as YourEntitiesDB;
if (db!=null && db.IgnoreSoftDelete)
{
// Ignore soft delete interseptor (Used in archives)
return;
}
if (interceptionContext.OriginalResult.DataSpace == DataSpace.CSpace)
{
var queryCommand = interceptionContext.Result as DbQueryCommandTree;
if (queryCommand != null)
{
var newQuery = queryCommand.Query.Accept(new SoftDeleteQueryVisitor());
interceptionContext.Result = new DbQueryCommandTree(
queryCommand.MetadataWorkspace,
queryCommand.DataSpace,
newQuery);
}
var deleteCommand = interceptionContext.OriginalResult as DbDeleteCommandTree;
if (deleteCommand != null)
{
var column = SoftDeleteAttribute.GetSoftDeleteColumnName(deleteCommand.Target.VariableType.EdmType);
if (column != null)
{
var setClauses = new List<DbModificationClause>();
var table = (EntityType)deleteCommand.Target.VariableType.EdmType;
if (table.Properties.Any(p => p.Name == column))
{
setClauses.Add(DbExpressionBuilder.SetClause(
DbExpressionBuilder.Property(
DbExpressionBuilder.Variable(deleteCommand.Target.VariableType, deleteCommand.Target.VariableName),
column),
DbExpression.FromBoolean(true)));
}
var update = new DbUpdateCommandTree(
deleteCommand.MetadataWorkspace,
deleteCommand.DataSpace,
deleteCommand.Target,
deleteCommand.Predicate,
setClauses.AsReadOnly(),
null);
interceptionContext.Result = update;
}
}
}
}
}
为了使用它,我只需在需要时将标志设置为true
YuorEntitiesDB DB = new YuorEntitiesDB();
DB.IgnoreSoftDelete = true;
DB.Records.Where(...)